An isomer of trisialoganglioside and the structure of tetra- and pentasialogangliosides from fish brain

Abstract

1. 1. The carbohydrate moieties from three gangliosides of cod fish brain were characterized. They contain three, four and five sialic acid residues, respectively. 2. 2. An isomer of the already known tri- N-acetylneuraminylgangliotetraose was isolated. It contains a NeuNAc-(α2,8)-NeuNAc-(α2,8)-NeuNAc residue linked to the C-3 hydroxyl of the nonterminal galactose of the gangliotetraose. 3. 3. Tetra- N-acetylneuraminylgangliotetraose, the carbohydrate of the major ganglioside from fish brain has the following structure: NeuNAc-(α2,3)- d-Galp-(β1,3)- d -GalNAcp-(β1,4)-[NeuNAc-(α2,8)-NeuNAc-(α2,8)-NeuNAc-(2,3)]- d-Galp-(β1,4)- d-Glc. 4. 4. In the pentasialoganglioside of fish brain the gangliotetraose is substituted in the 3-position of the nonterminal galactose by a residue consisting of three α2→8-linked molecules of N-acetylneuraminic acid and the terminal galactose in 3-position by two molecules of α2→8-linked N-acetylneuraminic acid. 5. 5. The neuraminidase from fowl plague virus was found so far to be specifically active toward the NeuNAc-(α2,3)-galactose linkage. In contrast, the NeuNAc-(α2,8)-NeuNAc linkage was split only very slowly confirming the result of R. Drzeniek And A. Gauhe ( Biochem. Biophys. Res. Commun., 38 (1970) 651).